Tablets are going to be a lot bigger than everyone realizes. We have been thinking this for the past few months, just after the first murmurs of sales volumes for the iPad, as we began to realize that it was perfectly capable of replacing some desktop PCs, many Notebooks and at least half of all netbooks, along with offering a number of entirely new service concepts.

Our financial partner in the US, TownHall Research, has come out with a best case/worst case report with Rethink input that points the way to over 500 million tablets by 2015, and as many as one billion of them shipped by then if we take all the upsides. By all means ask us for a copy of that report, and we will relay your request to TownHall and next month we plan our own second forecast in this market.

But this week we had one of the upsides in our view: the early entry into this market of Research in Motion, the Blackberry handset maker. Almost every blog and news article wanted to put down the effort of RIM, mostly on the grounds that as a company, it is not being adventurous enough in that it has aimed the PlayBook seven-inch tablet device fairly and squarely at its existing enterprise customer base.

This does two things for us which are unprecedented: it has made the device partner with its own handsets, and it has firmly invited enterprises to join the tablet market without the loss of control that can sometimes be felt when half of the executives of the company go off and buy their own iPhone/iPad or whatever device they fancy.

First the device: the PlayBook has a seven-inch capacitive touchscreen, just like the Samsung Galaxy Tab, and it will launch in the US early next year and internationally from the second quarter. No pricing was released.

The OS is a new one, not relying on the new BlackBerry OS 6.0, which despite a major update a few weeks back failed to set the world on fire when it appeared on the latest smartphone, the Torch. The tablet will instead run a new software platform, called BlackBerry Tablet OS, but based on Neutrino, acquired with QNX earlier this year. This has not been used much in mobile devices but has scored for robustness and content delivery, mainly as part of in-car systems, and it is already fully multitasking.

The lack of cellular connectivity on the device has been seen as a negative, but one of the main conclusions we are reaching is that everyone will need a tablet and a smart phone (or at least a phone) because there are some things for which you need your handset (voice, touch and go payments) and there are other things, which you would prefer to trust to your tablet – battery intensive activity, large screen operations like consuming content.

So we don't see this lack of cellular as negative, more a trend. Remember the Samsung Tab will not be cellular enabled in the US, despite having a Euro version with a radio chip. The Blackberry handset will convert a 3G signal into Wi-Fi to provide the PlayBook anywhere connectivity, but when in reach of cheaper connectivity such as your home Wi-Fi network, the Tablet connects direct. So you buy your tablet and use it with an existing 3G plan for some of the time, Wi-Fi the rest.

So naturally this new PlayBook has syncing capabilities with the BlackBerry, and secure pairing via Bluetooth. The RIM brand will immediately give IT departments everywhere an answer to “I want an iPad” without changing, tweaking or compromising the corporate email servers and corporate security standards, or even breaking any habits. This pairing idea is something we are likely to see even in Apple devices in next generation iPads and someone out there will invent a device which a detachable phone built in, we're sure of it.